Slanted Mirror
by Descendant of Truth
Summary: Before the events of the game, Sans is attacked in the True Lab, the results leaving him comatose and paralyzed. He gradually comes to his senses, but something seems off about him. As time goes on, everyone starts to wonder if he's really Sans anymore, or if someone else is controlling him… including Sans himself. Rated T mostly to be safe. Mild Alphys/Undyne.


_*You notice Sans is acting different than usual._

 _*You ask him what's wrong. He looks uncomfortable._

 _*…_

 _*It looks like you won't get anything out of him for now. Maybe try asking him again later._

* * *

"SANS! DO YOU REALLY PLAN ON SLEEPING THE WHOLE DAY?!" Papyrus bellowed from across the house. The response he got was almost inaudible, being so far away and its owner so naturally soft-spoken.

"day's barely started, bro..."

"IT'S ALMOST NOON, SANS," he emphasized, making his way to his lazy brother's door. "THAT'S HARDLY THE START OF THE DAY!"

A moment passed. Sans was always a little slow to respond after sleeping the whole night. That was one of the many reasons Papyrus hated to nap for too long; such drowsiness would not befit a member of the Royal Guard, even one in training!

"it's our day off, papyrus," Sans finally responded, "i don't have to go anywhere today."

"Which is exactly why you should!" Papyrus yelled, albeit at a more acceptable volume. "Without any obligations, we can have as much fun as we want! I already have plans to cook with Undyne today, you could come with! I'm sure she won't mind!" A tired groan and a shuffling noise came from the other side of the door. It sounded like he was either dragging himself into a sitting position or simply rolling over. Given that this was Sans he was dealing with, Papyrus suspected the latter.

"maybe i will. don't wait for me, though," he reluctantly answered. Papyrus let out a sigh. Getting Sans to get out of bed and do things was always challenging, but it was even harder on days they had off. The smaller skeleton just never seemed to have the energy for most things, even though he was relatively chipper most of the time. Still, he had never failed in getting his brother out of bed, and he wasn't about to start now.

All the same, he really didn't want to be late to his visit with Undyne, so he would just have to trust that Sans could get up by himself. He didn't _always_ need Papyrus' help, after all.

"Well, you be sure to call me if you decide to come with! I'm going to be leaving soon, and I don't want you just popping up out of thin air and scaring us again!" He berated, making his way down the stairs. If Sans made any sounds of acknowledgement, Papyrus couldn't hear him.

He didn't think much of Sans' laziness at this point, turning his attention to getting ready for the visit. He wasn't going to bring much, just some Mettaton videos to have running in the background while they cooked. Still, it would not do to be missing a video or to carry them haphazardly.

He checked the clock once he had picked out some of his favorites (picking _all_ of his favorites was impossible; they were all wonderful) and was glad to see that he was just in time to leave. But he wasn't about to leave without one final reminder to Sans.

"REMEMBER, YOU STILL HAVE TO GET UP TODAY! AND _CALL_ IF YOU'RE GOING TO COME WITH, SANS!" He yelled, receiving only a muffled acknowledgement in response. He supposed that would have to do.

Despite Sans' ever-persistent laziness, Papyrus was enthusiastic about the day before him. Spending time with Undyne always made everything better! And if he was lucky, maybe Sans would decide to come with him.

* * *

Sans stared at his door with a certain level of contempt. All he wanted was to stay beneath the nice, warm blankets and not move for the rest of the day, but that door was just standing there, like it was expecting him to come over and open it. In reality, though, it was Papyrus who was expecting him to leave the comforts of his bed. It was always Papyrus.

He took some comfort in that thought—that his brother was always there to make sure he kept going. It was that same thought that convinced him that maybe he _should_ try to socialize today. Now that he was finally starting to make real friends outside of Papyrus, he wanted to make sure it lasted. At least for a little while.

With as much determination as he could muster, he dragged himself out of bed and pulled on his blue jacket. Papyrus always cooked breakfast ever since he started learning from Undyne, but he had quickly learned that it was best to avoid eating anything Papyrus cooked if he could help it.

His first thought was to go to Grillby's for breakfast instead, but all the people there who would want to talk to him—even casually—might end up draining the social energy he wanted to save for later. Leftovers it was, then.

Munching on the large number of fries he had collectively brought back from Grillby's in the past week, he considered his options. He was seriously considering taking Papyrus up on his offer, but he didn't really know Undyne that well and she was a pretty exhausting person to be around. She had a kind of energy and vigor that reminded him of Papyrus, but she also had a habit of throwing spears around. He felt that made a pretty big difference.

He decided on visiting the door lady instead, just after he finished these fries. These fries that were taking far too long to get through. Why did he hoard so many? What made him think that he was going to need a stash of fries at some point?

Unfortunately, a quick shortcut and several unanswered knocks told him that she wasn't going to answer at the moment. That didn't leave him with many options.

Well, there was always Alphys, he supposed. The two of them had only recently gotten to regularly-speaking terms, as much as the two recluses could. He had been meaning to talk to her more lately; she was really nice, loved science just as much as he did, and always had an anime to put on.

The only downside he could think of was that he hadn't gotten her phone number and couldn't call to let her know he was coming. She tended to get flustered if caught by surprise. Oh, well. He had to do something with his day off, if only because Papyrus was so persuasive about it.

It was a bit of a stretch, but he pulled off a shortcut that took him all the way to Hotland. While he had never been too affected by temperature, being a skeleton, it was always a little jarring jumping from Snowdin to Hotland. All the same, the heat from the air reminded him of the comforting warmth of his blankets, and he suddenly felt inclined to close his eyes and take a nap right then and there.

But no, he came here to socialize, not take a nap! He shook his head to clear up the tired fog in his head. Sans knew exactly how easy it was for him to fall asleep anywhere at any time, but in a rare moment of determination, he fought against the urge. How embarrassing would it be to fall asleep on the way to someone's house? (Even if their house was more of a laboratory.)

It was only a short walk to Alphys' lab, which loomed above him in a way that would have been intimidating if he didn't know who it was home to. He approached the automatic doors and was a little surprised when they actually opened in his presence. Alphys usually had them locked. Still, he entered without too much caution. Maybe he could open up the conversation with a pun about doors.

Any potential conversation starter evaporated from his mind, however, when he saw that no one was in the room. The place only had two rooms; maybe she was upstairs?

Deciding that startling her out of her wits by suddenly warping into her room(?) was slightly preferable to ominously going up the escalator, he made a quick jump cut to the room directly above him and braced for a scream. But none came.

This room was just as empty as the first one. Sans couldn't help but feel himself grow more curious by the second, wondering where she was. He didn't know her to leave her home very often, other than to visit Undyne on occasion. But... Papyrus would have mentioned if Alphys was going to be there with them, as motivation to get Sans to wake up properly and come with him. So, where was she?

Taking the downwards escalator, he tried to keep himself from worrying too much. She was probably just out buying materials for her latest project. Still, there was something unsettling about going to someone's house—particularly a friend's house—to find their doors unlocked and the place empty.

 _Welp_ _,_ he thought to himself, _guess I'll be spending the day with Papyrus and_ _Undyne_ _, after all._ Although, he _could_ just take a nap somewhere. That could be nice. But at the same time... Papyrus. That was a hard call.

A call that he soon wouldn't have to make, as he passed a new set of automatic doors on his way to the exit. He stopped and looked at them curiously. They had definitely been there before, but he hadn't really noticed them before now. They slid open after he took a few steps towards them, revealing the inside to be an elevator.

Again, he felt that sense of unease creep up on him. These doors had never opened before, and Alphys never mentioned having a basement. Although, in hindsight, that would explain a great deal; like where she kept all of her equipment. Maybe Alphys was in there, and he didn't have anything to worry about. He should really be on his way by now.

Still... it couldn't hurt to check.

Stepping inside the elevator, he pushed the first button he looked at, and with a light _ding_ , the doors closed and the whole thing started to move downwards. Sans loved elevators. You could get from point A to point B without moving an inch, and unlike his shortcuts, there was time to doze off a little in between. Now, though, that nagging, unsettled feeling in the back of his mind kept him fully awake. There was no denying that he was growing concerned for Alphys, but this elevator and the unknown it was plunging him into certainly wasn't helping.

...Come to think of it, this elevator ride was going on for a _really_ long time. He hadn't spaced out and misjudged the time again, had he?

More time passed, and he was beginning to feel certain that he wasn't just dragging the seconds out. How far down was this basement? He was starting to consider warping down to get it over with sooner, but he knew that was stupid. Without knowing how far down it was, he'd either end up too high and hurt himself from the fall or aim too low and get stuck in the ground.

So, he was stuck. Somehow, the long elevator ride didn't do much to soothe his nerves. He just wanted to see if Alphys was down here and be done with it. The thought that he would most likely have to take this elevator back up made him groan in annoyance. He seriously hoped Alphys was in this basement just so that he wouldn't be bored on the way back.

After what felt like an eternity, the elevator stopped, and the doors swung open. The first thing he noticed when he walked out was that it was terribly lit down there. Of _course_ , it just _had_ to be difficult to see in a basement where he was looking for his friend. Everything just seemed to be set up to make him panic today. It was a good thing he didn't panic too easily.

This room must not have been used for much, being completely empty except for the elevator. He took the hallway to his left, somewhat glad that there was only one way to go. There was less ground to cover that way. The only thing of note were small screens attached to one of the walls, which immediately lit up as he passed them. The first one made him jump slightly; why did everything in this lab react to him so much?

He approached it, curious what the words displayed on the screen said, but the second he saw "ENTRY NUMBER 1," he decided it was better not to read it. It wasn't his place to read someone's notes, especially when they went to so much effort to keep them hidden. It would be like reading someone's diary! For all he knew, it _could_ be her diary! Besides, he was only here to find Alphys herself, not go through her things. And he wasn't sure he wanted to spend any more time down here than necessary.

The walk down the hallway was longer than he would have liked, but it paled in comparison to the elevator ride. When he finally entered another room, he wasn't sure what to make of it. It was much wider than the previous one, with a large door straight ahead that had four large circles on it. They almost looked like... keyholes? Beside it was a vending machine, which really shouldn't have been surprising, but for some reason it looked out of place.

Sans decided to investigate the large door before going through either of hallways on the far ends of the room. Just like everything else in the house, it was unlocked, and it pulled itself open when he got close enough. Amidst all of the other feelings in his chest that kept him looking this way and that, Sans found himself enjoying the lack of effort it took to get everywhere in this place.

At first glance, the room appeared to be empty. He thought it odd that such a large room wasn't being used for anything, but something on the far end of the room caught his eye. He stared for a moment, wondering if he was seeing things wrong, and decided to approach it to get a better look.

There was no doubt about it. Suspended in a large machine of some kind was a human soul, glowing vividly despite being trapped. About a hundred questions sprung to life in his mind at the sight, but the most prominent of them all was: _what_ _has_ _Alphys_ _been_ _doing_ _down_ _here_ _with_ _a_ _human_ _soul_?

And it was unmistakably that of a human's. Human souls came in a wide array of colors, like the bright red of this one, and were always upside-down. Not to mention the fact that it was impossible to preserve a monster's soul in the way this one was.

An impossibly loud, garbled shrieking noise shocked him out of his thoughts. He instinctually spun around, covering the sides of his head to block out the sound. He barely had time to process what was in front of him before his surroundings were dyed black and the tell-tale buttons of a battle appeared before him. His pupils shrunk down even further, almost more alarmed by the buttons than the actual threat. How long had it been since he was in a battle? He knew it must have been years, but it somehow felt a lot more recent than that.

He looked up at the three… things in front of him. They had no discernable shape or form, their bodies rapidly shifting from one position to the next, almost as if they were glitching. But that was impossible in real life, wasn't it? Sans had no idea how to comprehend the situation he was in right now.

As a result, it took him a moment to realize that they were giving him the first turn. It was practically a universal rule to take some form of turns during a battle, but somehow Sans didn't think that shrieking monstrosities like these would give him that option.

He took a deep breath in an attempt to ease the panic growing inside him, but it wasn't very effective with the freaky-looking things starting up their incomprehensible yelling again. After a brief moment of consideration, he made a break for it, deciding that fleeing was probably a better option than fighting at this point.

Unfortunately, none of the color returned to the room, and he was quickly blocked by the three shrieking things. That wasn't good. He was trapped in here with the living nightmare fuel, and from the looks of things, they were ready to start attacking.

Sans had no idea what to expect, but he was prepared to start dodging in whatever direction he had to. So when he was suddenly surrounded by small, white orbs that weren't moving, he was caught a little off-guard. He was practically about to start performing gymnastics to preserve himself, and their attacks weren't even dangerous?

Then they exploded.

Well, maybe "explode" wasn't quite the right term for it. But they rapidly expanded to over twice their original size, forcing him to duck and run his way around them to avoid getting fatally slapped by what looked like a deformed face.

He had to admit, nothing about their bizarre appearance would have made him think that they would use faces to attack. Usually there was some kind of similarity between a monster's appearance and attacks. Skeletons like himself used bones, fire elementals would use fire, flowers would use…

Wait, what? Since when did he fight a flower?

Oh well, it didn't matter at the moment. He just had focus on dodging. It was times like this that he was glad that Papyrus went through so much trouble to keep his agility up. Having such low HP was more of an annoyance than anything else, but it made fights far more dangerous to him.

The next few turns were more of the same: Sans trying multiple different actions to avoid having to fight while the distorted creatures threw a barrage of faces at him. He was becoming more worn down by the minute and was slowly being cornered near the human soul (which was the only thing that kept its color during the battle, he noticed).

This wasn't working. When he finally decided to select Fight and throw a complicated set of bones at one of them, it just absorbed the hit like it didn't do anything. He couldn't keep this up for much longer. Running away still wasn't working. What he needed was backup, but how was he supposed to-?

 _Oh_ , _duh_ , he realized as pulled himself away from another exploding face. He couldn't believe he forgot about his cell phone. He could call Papyrus, and then he and Undyne could help him get away from these things. He was feeling a little too impatient (and if he was being honest, panicked) to wait for the others' turn to be over, so he decided to just cheat his way into calling them. Papyrus picked up after the first ring, as usual.

 _"SANS!"_ Papyrus yelled a little too enthusiastically. _"You finally decided to come to my cooking lesson with me?!"_

"uh, actually, i need you two to come over to me," he replied, ducking beneath yet another face and feeling a little guilty that he didn't go with Papyrus in the first place. He sounded so excited. Still, he had more pressing issues to deal with, first. "i've gotten myself into a bit of a—hhgn!—Problem." He silently cursed his vocal instincts for interrupting his sentence, but he had to jump over the disturbing, mask-like face that spawned beneath him.

"What kind of problem? Are you alright? You sound strained! And what's that noise I'm hearing in the background?!" he sounded concerned now, which wasn't really what Sans wanted, but if it got him over here quicker, then he didn't mind too much. Come to think of it, their turn was lasting unnaturally long... were they cheating, too? If that was the case, then he _really_ needed Papyrus and Undyne to get over here.

"well, uh," he began as his back was pressed up against the soul container, "i'm kinda stuck between a rock and a hard place. Y'know—whoa!" He exclaimed, barely avoiding another onslaught, "if the rock was a wall and the hard place was a bunch of really freaky-looking monsters trying to kill me." His voice was only growing more panicked as he continued talking.

He was reluctant to call the things in front of him "monsters," but he didn't have time to grace them with a description. And he didn't have to for Papyrus to react, anyway.

 _"WHAT!?"_ He shrieked, his shrill voice managing to surpass the cacophony around him. _"WHERE ARE YOU?! I-I CAN BRING UNDYNE WITH ME! WE'LL HELP YOU, JUST TELL ME WHERE YOU ARE!"_

"i'm in a basement in hotland, just look for—" the sound of crackling electricity interrupted his thoughts, and his pupils all but vanished completely when he saw that the machine had been damaged by one of the faces. The human soul was also vibrating strangely, probably in response to the damage. He had to get away from the machine as soon as possible, but all these exploding masks were making it impossible to plot an escape route.

Everything happened too fast. The electricity popped, the human soul glowed with such intensity he could see it with his back turned, and a searing pain shot through him, cutting so deep it was indescribable. He could only manage a strangled yell before everything went dark. The last thing he noticed was that the things had stopped attacking.

Oh... of course _that_ was when they ended their turn...

* * *

Alphys was used to hearing screams down here. They haunted her, constantly reminding her of her failures. It wasn't a constant, but it hardly took her by surprise anymore. She always felt her worst when she came down here, but someone had to take care of the amalgamates. The mistakes _she_ created. She couldn't afford to fail them anymore than she already had.

Still, it was impossible to mistake the pained cry from across the lab as anything but a normal monster. She jolted up from where she had been feeding the amalgamates, fresh fear taking ahold of her as she ran towards the sound of the scream. No, no, no, she couldn't let another innocent monster get hurt because of her! She should have noticed that some of them were missing, why was she so _stupid_ to let this happen?!

Even at her top speed, it felt like it took too long to make it to the generator room. She could only pray that she heard correctly and hadn't entered the wrong room by mistake. Thankfully, she was correct in her assumption, but that was the only positive thing about the image that greeted her.

The generator was smoking, clearly damaged, three of the more unstable amalgamates crowded around it. But she couldn't see who had screamed.

"H-hey!" She shouted, getting the amalgamates' attention. "If it's food you want, then I have some right here! Y-you don't have to a-attack anyone for it!" Her voice portrayed little strength, but it was loud enough to be convincing to them. She threw the bag of food outside the room and they hastily chased after it. With them cleared away, she could see who the victim was.

It was Sans. He was collapsed against the damaged generator, his eyes wide open but without a hint of light in them.

"Oh, no..." she whispered. In only a brief moment, she was at his side, which was when she belatedly noticed the cell phone beside him. Someone was on the other end of the line, shouting in panic. She must not have noticed it at first above the amalgamates' din.

 _"SANS! BROTHER, TALK TO ME! Y-YOU'RE GOING TO BE OKAY, UNDYNE AND I ARE ON OUR WAY RIGHT NOW, JUST PLEASE HANG ON!_ " The voice shouted. It was unmistakably Papyrus, Sans' brother. He must have called for help when he started being overwhelmed. That thought made her feel even worse.

She fumbled with the phone for a minute, feeling that she should give Papyrus some closure on his brother and hopefully keep him out of the lab until she could stabilize him.

"H-hello?" She mentally slapped herself for opening with such a casual phrase, but Papyrus interrupted before she could say anything more.

 _"WHO IS THIS?! I-IS SANS WITH YOU, IS HE ALRIGHT?!"_ His voice was so loud that he had to hold the phone away from her to protect her eardrums but brought it closer when she had to speak.

"Th-this is Dr. A-Alphys! Yes, h-he's here. But he's in p-pretty bad sh-shape, so I'll n-need you to s-stay outside the lab until I c-can get him s-stable. Can you d-do that for me?" She asked, hoping that Papyrus would be willing to listen. There was a pause. Papyrus was most likely wondering if he could trust her, if she were to take a guess. What reason could he have to trust her, after all? She didn't even trust herself with this. Not fully. When he responded next, though, he sounded marginally calmer.

 _"...Alright, but I want to be with him the second he's okay! Please take care of him, Doctor!"_ With that, the phone made a clicking sound and the call ended.

She sighed. Papyrus sounded so desperate in that last sentence; she _couldn't_ fail this. With some difficulty, she lifted Sans off the ground and carried him to an old, movable hospital bed. At least then she could push him to the elevator easier.

There had to be a way to make this work. There just had to be.

* * *

 _*You ask Sans if something had been troubling him earlier._

 _*"nah,_ _i'm_ _alright. just some..._ cold feet _,_ _y'know_ _? heh_ _heh_ _."_

 _*"...honestly, it's kind of a long story. don't worry, though. he'll tell you all about it once he's ready."_


End file.
